He was taken from the practice field in an ambulance Tuesday after taking a hit to the head and neck.

The team said he was taken to Stanford Medical Center.

"After evaluation, doctors determined Newsom has no cervical spine fractures, but did suffer a concussion," the 49ers said. "Newsom remains at Stanford Medical Center under observation."

Coach Kyle Shanahan said earlier in the day that Newsom had feeling in his arms and legs and his eyes were open as he was put on a stretcher and taken to a hospital. Newsom lay motionless on the field for nearly five minutes after colliding with safety Chanceller James while trying to break up a pass during a two-minute drill.

Newsom joined the 49ers in May as an undrafted free agent from Missouri.